The Mithraism which was a part of the Iranian ancient culture and religion during the Arsacid Dynasty (248 BCE-224 CE) had been expanded and so far, many temples have been found in Iran and of course in East Azerbaijan. Mehr Temple in Maragheh is one of those temples that has a long history. Maragheh is one of the most ancient cities in Iran that its suburbs in the past had several temples related to Mithraism. The underground Mehr Temple is located in the Verjuy Village, and the adherent of Mithraism created the temple by cutting a huge schist stone on the ground. When you enter the temple, there is an underground hall with a crescent-shaped ceiling at the beginning of the cave. There are a number of holes which are connected to underground with a dome-like roof. These holes were made to let the light in. There are Qur’anic inscriptions on the wall and entrance written in Naskh script. Unfortunately, some of these inscriptions were destroyed over the passing of time. There is a platform with two steps at the end of the main hall that reaches a small wooden door. There is a circular hall as high as 6 meters inside the temple which is made of stone and consists of beautiful vault rows that go around the wall. According to Cultural Heritage, Handicrafts and Tourism Department of Maragheh, the temple was a place for worshiping the sun and a place for holding ceremonies before the arrival of Islam, but after that, it was used as a mosque. The most important part of the temple was its Mehrab (Altar) which was located at the end of the hall and it was considered as a window opening to God and the reality of this world. There is also a narrow hall between altar and the entrance.